Method and apparatus for manufacturing inflated rubber articles



-N. D. `CRAWFORDl METHOD AND APPARATUSIOR MANUFACTURING INFLATED RUBBER ARTICLES.

, APPLICATION FILED SEPT. `2.2, 1920. -1{3 65,462-.`

2 SHEETS-SHEET l.

VIII/11,111,111

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l I I l l lul N..n. CRAWFORD.' n y METHOD AND APPARATUS FORV MANUFACTURING I'NFLATED RUBB'ER ARTIGLES.`

, Armcmowmzo sEPT. 22. 1920.v 1,365,462.

31, hit eutmetgf v I Patented Jan. 11,1921.`

, ratus UNITED lSTATES PATENT OFFICE.

NEIL D. CRAWFORD, OF MILFORD, CONNECTICUT, ASSIGNOR TO THE MECHANICAL RUBBER COMPANY, A CORPORATION OF NEW JERSEY.

METHOD AND APPARATUS FOR MANUFACTURING INFLATED RUBBER ARTICLES.

Application `filed September 22, 1929.

To all whom it may concern:

Be it known that I, NEIL D. CRAWFORD, a citizen of the United States, residing in the city of l\Iilord,` county of New Haven` and State of Connecticut, have invented certain new and useful Improvements in Methods and Apparatus for lllanufacturing Inflated Rubber Articles, of which the following is a full, clear, and exact description.

This invention relates to the manufacture ot' hollow rubber articles ot' that general class which have greater internal pressure than the atmospheric pressure upon the ex terior. The invention relates particularly tothe manufacture of tennis balls and similar articles which are formed in parts, the several parts being united while the article is being simultaneously inflated, and final vformation being given to the intl-ated article by vuleanizing it ina-mold. c

This application is a continuation in part of my application Serial No. 53,191, filed Sel'itember 29th, 1915.

The object of the invention is to produce an apparatus in which the shaping, Limiting, and inflating operations may be accomplis-hed quicker than hitherto and more etlicient-ly. This end I attain by the provision of simple mechanism for simultaneously v shaping the parts ofthe article, and for then simultaneously uniting the parts and inflating the article. .The device is so constructed that the movementv of the parts carrying the rubber stock is toward and away from each other during all the various operations performed, and said parts are used continuously without transferring the stock therefrom during any stage of the process.

For a detailed description of one `form i of my invention reference may be had to the following specification and to the accompanying drawing, 1n which- Figure 1 1s a side elevation of the appa- F ig. 2 is a sectional View on the line 2-2, Fig. 1;

l Fig. 3 is an enlarged sectional view showing the sections of the mold about to be closed upon the core to form the halves of the rubber article therebetween;

Fig. 4 is a sectional view similar to Fig.

3 vand showing the sections ofthe mold closed upon the core;

Fig. 5 is a sectional view showing the Specification ot Letters Patent.

rammed aan. 11, 1921.

Serial Ne."41,892.

pressure chamber for infiating the article during closing of the `molds after removal of the core;

F 1g. (3 is a sectional view showing thee the line .lar parts, 10` designates a support from which rise standards 11 that support opposed cylinders 12 which are disposed horizontally in axial alinement. Within each cylinder is a piston 13 the rod 14 of which projects through the head 15 of the cylinder and is terminally equipped with a holder 16, and further is made hollow at its opposite or inner end and provided with a pin 47 which projects in a slot 48 of a pin 49 secured to the end of the cylinder 12 to preventrotation of the rod 14 and the parts carried thereby. Each holder is provided on the front face with a semi-cylindrical shoulder 17 having a groove 20 at its inner face at the juncture with the holder.

Each holder removably supports a section 19 of 'a mold, the section being cylindrical inoutline and bearing within the shoulder 17, and

having a flange'lS at the inner end which is received within the groove 20 in the shoulder and anchorsfthe section against withdrawal in any direction except vertically,

' pins 50 being provided in the flanges 18 and disposed to seat in corresponding grooves formed in the shoulder 17 to prevent the section 19l from rotating. Each mold section is formed with a hemispherical recess- 2l in thelfront face, the recesses coperating in forming a sphere when the sections are closed. The-sections are moved in axial alinement toward or away from each other by the pistons 13 which are acted upon by compressed air or other medium under pressureadmitted and released through valve controlled pipes 22 and 23.

Carried upon a vertical piston 24 between the mold sections 19 is a core 25 of such v*shape as to lie-received within the recesses 21 of the mold sectionsand conform to the Vform of a scribed. The flange carries dowels 27 which engage in corresponding openings 2 5'in the mold sections and position the core inaxial alinement with the sections so that the product will be symmetrical.l By means of the piston 24 theI core may be withdrawn out of the path of movement of the mold sections to-permit closing of the mold sections together to unite the parts of the article, as will be presently described.

Slidably fitted on each cylinderwand secured against rotation by the feathers 5l. is a casing 29'having an inwardly extending flange 3() on the front end. The flange of one of the casings carries `a packing ring 3l whereby when the anges are in abutting contact at the inner limit of movement ot' the casings a fluid tight joint will be produced. )ne casing is provided with a circumferential flange 32 which fits over the opposite casing and reinforces the joint when the casings are closed. After withdrawal of the core out of the path of movement of the casings, the casiiigs may be moved inwardly to closed position by means of racks 33 engaging a pinion 34 which is rotatedby a handle lever IWhen closed the casings form a chamber for a `Huid under pressure which is supplied through a pipe 36 which carries a pressure indicator 37. To lock the 'casings closed pivoted clamp bolts 38 are mountedoii one of thel casings and engage in lugs 39 on the opposite casing. p

For locking the mold sections together preparatory to placing the mold in thevulcanizer, a substantially U-shaped spring clamp 40 is placed astride of the sections, there being grooves 4l in the sections and mating grooves 42 in the holders to accommodate the ylegs of the clamp and promote applying the clamp to the mold section While they are still contained within the holders. The clamped mold sections maybe withdrawn vertically from ,the holders, the grooves in the sections then operating to anchor the clamp against twisting` and accidentally releasing the sections.

To produce tennis balls by this apparatus, rubber stock which has been reduced to the requiredgag on a calender, is cut into the altese cross as shown in Fig. 7. The edges of the'cross are brought together to produce a'cupshaped member of raw rubber having substantially the required dimensions to fit nicely within the corresponding mold section and which subsequently forms one'half of the ball. When both mold sections have been equipped with tions together.

the pressure mediuinisa'dmitted behind the pistons whereby the molds are moved toward and compress and shape the stock against the core 25' which hasfbeen previ- Voiisly brought into axial alineiii`eiit\\'ith the mold sections. The surplus stock is squeezed into waste grooves 43 formed iiithe flat4 faces of the molds, the grooves being so ,shaped as to form cutting edgesy 44 which lthem the shaped rubber halves, it being understood that the mold sections may be heated if desired: to prevent displacement of the halves therefrom, but this isnot essential since the weight of the halves coming `upon the lower wall of the recesses 21 will of itself prevent displacement.

By means of the piston 24 the core is now A lowered out of the path of movement of the casings 29, and the latter are moved iiiwardly to closed position by rotation of the crank handle 35 and are then locked closed.

Compressed air or other desired vmedium under pressure is now admitted through the pipe` 36 to the chamber formed by the casings, vthe pressure indicator 37 indicating the risingpressure so that the medium may be cut off at the desired point.

Next, pressure is' again applied behind the pistons to move the mold sections inwardly into intimate contact with each other, and during such movement a quantityy of the fluid underpressure in thel chamber Will be entrapped between the sections of the rubber article so that when the edges of said sections meet and are united by complete closingA of the mold sections, the resultant spherical ball will be in-4 flated and will have an internal pressure H by the edges 44, thus producing a ball 4G i which is devoid of seams or other inequalities in inner or outer contour. e yThe casings 29 are now unlocked and moved apart to facilitate insertion of the U shaped clamp 40 to clamp the moldV sec- Th'e clamped mold is r'emoved vertically from the holders 16v and transferred to a vulcanizer Where vulcanization is giventothe ball by any usual or preferred process.

the Vcupshaped rubber halves of ,the ball,

' icing 1 Various modifications may beresorted to within the scope ofthe appended claims without departing from the spirit or sacriany of the advantages of the invention. v f

What is claimed is: i 1. An apparatus for making inflated hol- 4low articles comprising mold sections and a removable core between them for simultaneouslyt shaping the component parts of the article, means for surrounding said moldsections with a fluid under pressure, after removal of the core, and means for actuating the mold sections to unite said component part-,s within the enveloping fluid under pressure.

2. An' apparatus for making inflated holfor closing said mold sections to unite the component parts of the article withinsaid enveloping fluid underpressure, and means for ,clamping the closed mold sections `together,1 l

3..An apparatus for making inflated hollow rubber articles comprising relatively movable moldffsections, a removable core be- 'tweenthe sections and coacting therewith in simultaneously shaping the component parts of `the article,` means for .enveloping 'y said mold sections in a fluid under pressure after removal of the core, means for 'moving said mold sections in axial alinement into' closed position whereby the component parts of the article are united and'a portionof the fluid under pressure entrapped in the article, and means for clamping the closed mold sections together.

4. An apparatus for making inflated hollow rubber articles comprising relatively' movable m'old sectio"ns,'a removable core between the sections and coacting therewith in simultaneously shaping thecomponent parts of the article, a casing for inclosmg the mold sections and enveloping the same in a fluid l under pressure, means for moving the mold sections 1n axial allnement into closed posl- Y tion for uniting the parts of the article while envelo d by said fluid under pressure,`means or w1thdrawin the casing to expose the. closed mold sections,` and means ing the complementary edges for clamping the closed mold sections toto lthe holders, a removable core between the mold sections boacting therewith for simultaneously shaping the component parts of the article, neans for moving the pistons to open and close the mold sections, means for enveloping vtheA mold sections during their asis` closing movement in a fluid under pressure,

`and means for clamping the closed mold sections together. y s 6. The method of manufacturing an in- -flated hollow rubber article with mold and core sections consisting in pressing the mold `sections against the core section to form blanks into parts of an article, withdrawing the core section, bringing the mold sections together to unite the edges ofthe article parts while in air or gasunder pressure, and subse uently vulcanizing the article.

7. he method of making inflated hollow rubber balls consisting in cuttin crossshaped blanks from sheet rubber, su jecting the interior and exterior surfaces of both blanks simultaneously to the pressure of rigid mold walls to form all the parts of the article with complementary joining edges, said'parts being formed while maintainingl them in oppositely disposed alined positions for uniting them, uniting the parts by brin to ether while maintaining their alinement and while supported exteriorly bythe mold walls and surrounded in a fluid under pressure, holding them in this position until said edges have adhered, transferring the ball to a vulcanizer, and finally vulcani'zing the article while'v the pressure is maintained within it and'the article is maintained within exterior rigid mold walls.

Signed at New Haven, Connecticut, this thirteenth dayv of August, 1920.

NIL nv CRAWFORD. 

